"The U.N. is both stunned and appalled by the enormous quantity of weapons being illegally held in Banja Luka police stations," said Liam McDowell of the U.N. International Police Task Force. "In one police station alone, the weapons cache included hundreds of fragmentation grenades, machine guns, rockets and rocket launchers, a large array of explosives and much more besides. These are not the tools of a democratic police force."

About 300 NATO Stabilization Force troops from the British sector met no resistance when they entered police headquarters, three police stations and the police academy at the request of the U.N. police task force. International authorities asked for NATO's help after acquiring evidence of widespread human rights violations, said Navy Capt. Mike Doubleday, Pentagon spokeman.

"This comes under the rubric of creating a secure environment and supporting the International Police Task Force," Doubleday said at a Pentagon briefing Aug. 21. "The basic goal of SFOR units is to create this secure environment that will enable civilian authorities to do the work they must do to ensure Bosnia can get on its feet as a country."

During the early morning raid, SFOR troops discovered assault and sniper rifles, machine guns, thousands of rounds of ammunition, mines and explosives. Some of the weapons are outlawed by the Dayton peace accord and others exceed amounts civil police are authorized to maintain, Doubleday said.

Some weapons confiscated were more likely to be found in a movie thriller or in the hands of terrorists, said Alex Ivanko of the International Police Task Force. SFOR troops found "a couple of items that actually belong more in a James Bond movie than in a police station -- 12 booby-trapped pens, C4 plastic explosives and one U.N. license plate," he said.

Under the Dayton agreement, the U.N. task force oversees the restructuring, training and equipping of local police. It also investigates alleged human rights abuses by local police and recommends removal of abusive police. Task force members are unarmed.

In an investigation two days before the raid, task force authorities uncovered highly sophisticated listening equipment at a civil police station. Evidence indicated police were eavesdropping on local government officials, constitutional court judges and international agency officials, a U.N. official said. Hundreds of tapes were removed from the police station, according to U.N. representative Simon Haselock.

"The United Nations can confirm they have unequivical evidence of serious criminal activity being conducted in the main Banja Luka police station," said task force representative McDowell. "This includes the bugging of the (Republic of Srpska) president's communications."

A week before the raid, about 12 U.S. helicopters -- Apaches, Chinooks and Black Hawks -- U.S. F-16 and United Kingdom Jaguar fighter jets participated in an air assault exercise about 100 kilometers north of Pale, Bosnia. SFOR troops practiced conducting airmobile assaults and inspecting weapon storage sites with local military and civilian officials. DoD officials said the exercise was one of four conducted in the last three months, and more are planned.

More than 8,200 U.S. forces are in Bosnia as part of Operation Joint Guard. About 4,000 more support the NATO mission from Croatia, Hungary and Italy. About 3,000 U.S. troops are currently deploying to replace troops scheduled to leave.

Some incoming troops will supplement existing forces during Bosnian municipal elections Sept. 13 and 14. Most deployments and redeployments will be frozen during September and will resume about Oct. 1, DoD officials said.